On March 8, 2016, FDA has issued a letter to the healthcare providers, particularly cardiologists and electrophysiologists, regarding tampering of anti-tachycardia activity of implantable-cardioverter defibrillators (ICDs) or pacemakers when placed in close proximity of breast tissue expanders with magnetic ports.
It is found that breast expanders with magnetic port used in women with mastectomy for reconstruction of breasts, disturbs the electro-cardiac activity of the pacemaker and this way people with pacemakers installed experience arrhythmias.
FDA has made a new rule that it is mandatory for the breast tissue expanders with magnetic ports to bear a warning sign on them for women with pacemakers or cardiac electronic devices installed already.
Implantable-cardioverter defibrillator (ICD) is an electronic cardiac gadget that is placed under the skin of patients with ventricular tachycardia or fibrillation to keep track of abnormal rhythmic beats in the heart and it delivers an electric shock to the heart whenever it detects an abnormal beat in the heat. The electric shock or energy forces the heart to pump in rhythmic fashion, thus restoring the heartbeat. This device possesses dual properties as it also functions as a pacemaker.
A pacemaker is a small cardiac electrical device that uses batteries to treat arrhythmias. Arrhythmias are irregularities in the rate or rhythmic beats of the heart, causing it to beat either slowly or miss a beat. A pacemaker is placed either in the heart or in the abdomen to regulate the heartbeats by connecting it with wires to the heart. The device transmits electrical pulses to the heart and compels it to beat at the normal rate or pace.
Breast tissue expanders are actually temporary breast implants – a prosthesis comprising a gel-like or aqueous material in a ductile sack, so that the breast skin and muscles are expanded over a period of time for the permanent breast implant in the future. The process is a part of a cosmetic breast surgery to reconstruct a dummy breast for patients undergone mastectomy.
Some of these breast tissue expanders have magnetic ports to fill the breast tissue expander with saline solutions periodically, so that the tissue expands or inflates over a period of time, giving the dummy breast a soft padded feel and tenderness like a natural breast and also making space for fixing permanent implant in future.
FDA reported that several reports and case studies have been documented by various categories of health care providers, stating that when these breast tissue expanders with magnetic ports are placed close enough to the ICDs or pacemakers – approximately at 1 inch distance between both electronic accessories, the magnet port brings about magnetic interference and compels the ICDs to go into “magnet mode” – a state in which the anti-tachycardia activity of ICDs is arrested or disturbed, exposing the patient to irregular heartbeats which may be life threatening for the patient.
The patient, however, is able to sense this magnet mode as the ICD or pacemaker continuously beeps without sensing the abnormal heartbeats due to inability to curb these abnormal rhythms and the patient can feel the heart palpitating.
A special case study is reported by Dr Agarwal and his team in Arrhythmia Grand Round, about a 57-year-old woman, in whom a peculiar sound was emanating from her ICD. The woman was suffering from ventricular tachycardia along with other physiological and morphological complications of the heart and so an ICD had been inserted in her chest to control these irregular ventricular beats.
After some years she developed breast carcinoma so mastectomy was performed. Later, breast tissue expanders were implanted to reconstruct a dummy breast.
The breast tissue expanders had to be filled with saline solution to inflate them and give the dummy breast a cushioning or padded feeling. After the third filling was performed with saline solution, the patient gradually started feeling that a distinctive sound has started arising from her ICD.
The patient reported about a peculiar sound to her cardiologist with no other complaints regarding her health and so thorough interrogation regarding the patient’s cardiac device functioning was carried out. During the process, the patient’s history revealed that in the near past her ICD battery had been repositioned and was now placed close enough to the breast expander tissue.
The history revealed that since the sound prompted after third filling of the breast tissue expander had been performed, so something related to the filling of the tissue expander was accountable for the induction of the sound.
Dr Agarwal and his team searched the scholarly literature regarding this matter and found that similar reports have been documented by other researchers. Later, in an ex vivo environment experiment it was found that when a breast tissue expander with magnetic port was brought closer to an ICD, a magnetic resonance was produced which intercepted with tachycardia therapy, that is, the ICD was not able to detect any abnormal beats in the heart and therefore could not resolve the irregularity in the rate and rhythm of the heart.
When the breast tissue expander with magnetic port was placed at a distance, the magnetic resonance ceased and no sound was heard. The ICD also worked properly without any hindrance.
It was also unearthed that this distinct problem arose only with tissue expanders with magnetic ports but not with tissue expanders with non-magnetic ports.
So, according to FDA rules and regulations, the breast tissue expanders with magnetic ports must bear a warning and contraindication that such tissue expanders should not be used in conjunction to other cardiac electronic devices in heart patients that also require breast reconstruction and that if the case need be, the cardiac electrophysiologist should either change the position of the ICD or a breast tissue expander with a non-magnetic port be used.